OpAmps for the Viper-D2?
Mar 18, 2008 at 3:07 PM Thread Starter Post #1 of 126

greenzee

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Looks like there's some conversation already about different opamp combos in another thread, wondering if we can start a new thread specifically about what works, and what doesn't, in the D2?

I've never rolled opamps before in any amp, so I'd love a primer on in general what size/type/? opamps should work in this amp, so I can buy some and experiment.

And of course, anyone who's got a tried and true opamp combo for the D2, please let us know.
 
Mar 18, 2008 at 7:57 PM Post #2 of 126
My vote for NUMERO 1 D2 Combo is: LM6172 in both IC2 and IC7 sockets, followed closely by ISL55002IB in IC2 and THS4032 in IC7.

The LM draws much less power, and provides truly outstanding dynamics, realism, and soundstage. An added bonus is that this opamp is available in DIP configuration which allows "Plug & Play", no adapters required.

The ISL/THS is a closer soundstage, more completely immersing one in the music.
 
Mar 18, 2008 at 8:35 PM Post #3 of 126
Quote:

Originally Posted by HiFlight /img/forum/go_quote.gif
My vote for NUMERO 1 D2 Combo is: LM6172 in both IC2 and IC7 sockets, followed closely by ISL55002IB in IC2 and THS4032 in IC7.

The LM draws much less power, and provides truly outstanding dynamics, realism, and soundstage. An added bonus is that this opamp is available in DIP configuration which allows "Plug & Play", no adapters required.

The ISL/THS is a closer soundstage, more completely immersing one in the music.



do you know any place that sells them?
 
Mar 21, 2008 at 6:45 PM Post #4 of 126
Anyone that tried any other opamps for the D2?

I'll probably visit an electronics store in the next few days but I believe that they'll have to order the LM6172 unless it is an often used opamp.
 
Apr 30, 2008 at 1:30 AM Post #5 of 126
Looks like most of the opamp info is burried over in the other 58 page D2 thread... <gack> I'm sifting through and thought it made sense to summarize opamp & mod info over in this thread...

HiFlight mentions his favorites above (and he offers those 4 as a kit, I understand). But looks like he tried some others as well:

Quote:

Originally Posted by HiFlight /img/forum/go_quote.gif
Well, the OPA2134 sounds pretty good in IC-7, and AD746, OPA6172 and AD8066 sounded good in LR, as well as ADA4847-1, but after all the rounds of trials, I ended up back at the same place I started. 55002 in LR and 4032 in IC-7. LMH6655 did not work at all in IC-7 but didn't sound bad in LR. LME49720 lacked impact and had a rather restricted soundstage.

I don't really think the cost of the 55002 and 4032 is that much higher than many of the others, considering the superb performance and the fact that only one of each is required in this amp.

Of course there are many other sets of ears that could well prefer something other than what I like.

...The ISL55002IB is made by Intersil and the THS4032 by Texas Instruments...



 
Apr 30, 2008 at 1:32 AM Post #6 of 126
A couple more mentioned here...

Quote:

Originally Posted by powertoold /img/forum/go_quote.gif
The AD74x series isn't free...

Right now I'm using the AD8599 in buffer and AD4841-2 in main.



 
Apr 30, 2008 at 1:57 AM Post #7 of 126
More from HiRoller...
Quote:

Originally Posted by HiFlight /img/forum/go_quote.gif
For want of anything better to do, I decided to try to see how close I could come to the sound of my iQube. As neither my D2 or my iQube have many hours yet, this comparison may not hold up, but I found that the soundstage of the ISL55002/THS4032 was different than that of my iQube. Tonally, they were closer than one would imagine considering the difference in cost.

After trying several of my "top tier" opamps, I found that the combination that sounded the closest to the iQube was the LM6172 in both IC-2 and IC-7. This combination moves the soundstage further away as compared to the previous combo.

Bass is tamed a bit more and a little tighter. Depth of soundstage is greater, but for those who prefer to be immersed in the music, maybe the 55002/4032 might be preferable.

I wouldn't say one is really better than the other, just a little different with the 6172s more similar to the iQube, if that is the sound one prefers.

A couple of bonuses in favor of the 6172 is that it draws only 2.3 ma per channel while outputting about 50 ma/channel. It also is available in DIP configuration, which means no adapters are needed.

I would be interested in hearing comments regarding your opinions and comparisons of these 2 configurations.



 
Apr 30, 2008 at 1:59 AM Post #8 of 126
Quote:

Originally Posted by powertoold /img/forum/go_quote.gif
I don't recommend the ISL55002 opamp for IEMs. They are too noisy, and they don't seem that great with my headphones either. I went back to my 4841 and 8599 in buffer.

Edit: I switched the 8599 to the main opamp and put the 4841 as buffer. I think this is a great combination for me because it sounds a bit lighter on the bass. I thought my FreQs were bass heavy with the other opamps, so this works for me. I totally recommend the AD8599 for IEMs. They're great.



and
Quote:

Originally Posted by powertoold /img/forum/go_quote.gif
With the AD8599 replacing the LT1364, the D2 sounds amazing with IEMs. omGJdklsfkas there's almost no background hiss with my sensitive FreQs. The soundstage, imaging, speed, and clarity are top-notch. I love it. I hope there are better opamps out there too! I love opamp rolling ability!


 
Apr 30, 2008 at 2:08 AM Post #9 of 126
Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif
Now that I am done burning in the D2 I am going to roll in the two 6172 Friday/Saturday. I will also try the ISL50002 and THS4032. Stay tuned...

I just have to remember if I have both 6172 yet, I know I have one of them...



...
 
Apr 30, 2008 at 2:10 AM Post #10 of 126
Quote:

Originally Posted by powertoold /img/forum/go_quote.gif
...Now I'm using double AD8599, and it charges quickly and predictably (for some reason with other opamps, this doesn't happen)...

If you plan to use IEMs with the D2, get a AD8599. Once you go 8599, there's no turning back!



...
 
Apr 30, 2008 at 2:15 AM Post #11 of 126
This post is about changing out the volume pot for a better ALPS version...
Quote:

Originally Posted by MONVMENTVM /img/forum/go_quote.gif
OK just looked at the ALPS homepage and already found the type of pot that is used in the D2 (though I don't know if the one in the D2 is an ALPS... mine is blue while on the ALPS homepage it is black).
You can see it here:
RK097/RK098 Series|Basic information

There are many different types. For example this would be the right one without a switch:
RK097/RK098 Series|Basic information

Or some with push switch... here is the whole list of them which should fit. You can even get them with different resistance taper:
RK097/RK098 Series|Products Line



Quote:

Originally Posted by MONVMENTVM /img/forum/go_quote.gif
OK I planned a bit around and in the meantime I also managed to ask iBasso from what company these pots are. If they're from ALPS (what I don't believe) than it would make no sense to buy and replace them with the same RK0971221Z05 pots as it is likely that they will start scratching after some days again... though I don't believe that they also would.
Anyway in this case I would buy a RK09712200MY which in fact is the same pot but without the switching capability. Because of this they are also about 6mm shorter than the ones with switching but they would fit perfectly nonetheless. But because of the fact of being shorter I have access to the contacts for switching the amp on and off. That way I can easily access the contacts. All I have to do is to unsolder the gain switch and resolder it with 2 short cables that connect to where the pot was before. That way I would have a separated on/off switch and potentiometer working flawlessly.

For the gain switch I would take something like this:
http://img-europe.electrocomponents....R339673-01.jpg
...and place it somewhere inside of the amp as there is still plenty of room. For example above the input/output connectors. If someday I'd have too much time, I could even drill a hole on the backplate somewhere so that the Gainswitch remains accessable from the outside. But I don't need the gain switch much anyway.



 
Apr 30, 2008 at 2:20 AM Post #12 of 126
Some tips for checking opamps off the beaten path...
Quote:

Originally Posted by HiFlight /img/forum/go_quote.gif
Check the opamps data sheet to see if the voltage requirements are appropriate. Try to use opamps that will tolerate at least 10 volts. Low noise is good, As a rule, better square-wave response usually results in better audio quality.


 
Apr 30, 2008 at 2:35 AM Post #13 of 126
Here's some substance...
Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif
Here are my notes I took as I rolled opamps in my D2 and listened:

1) I am first listening to the ISL55002 in main (replaced the 1364) and and THS4032 in the second spot (replaced NE5532). This is really nice with the ALO modded 780's (in same room as sleeping wife, so no open phones).

It is not what I expected, but rather with strong bass, smooth highs that are less accentuated than stock when teamed with the 780, and it's very transparent. Pianos and snares are crisp and attack and decay is good. Drums sound good, and bass guitar is tight. Saxophone are nice but maybe a liittle of the warmth is missing on those. Diana Krall's voice in "Temptation" does not have sibilance, and that is my test track for sssssibilance. I have no trouble hearing the knocking artifacts from the piano in "Departure Bay", from pedals and such. Next, the 6172 x 2.

2) Immediately I hear the sound is more forward with the LM6172 x 2, and some of the background is pushed out of the way to make the singer come forward. It is a more intimate warm mellow sound, reminiscent of the first time I heard the Meier Headsix.

The sound of the piano pedals is more of a booming low frequency background noise, makes me want to look up an look for where it coming from. Saxaphones seem to be lacking a little bit of the reedyness, but they are warmer.

Playback volume seems lower too. YIKES!!! I just flipped to high gain since the volume was low, and lost the left channel! And it's not the headphones or macbook. This is gonna suck - unplugging it and turning it off didn't bring the left channel back, and all I did was flip the gain switch just now.

Arghhhh!!!

3) Can't believe I am continuing this after my scare. Turning off, unplugging, and removing and replacing the the opamps with stock ones got me both channels back. It sounded good enough that I almost quit right there. But, I wouldn't be a HeadphoneAddict if I didn't keep going.

I think that one LM6172 (soic on browndog) plus stock NE5532 offers more volume than two 6172, and offers a less closed in sound, while still being a little intimate. This still tames the treble for me.

I immediately swapped the 1364 back in, and I moved back from 1st row to 3rd row, with a slight jump in highs and less warmth. The two 6172 has me ON the stage, but I like one LM6172 + NE5532 better than two 6172.

Leaving the NE5532 I then swapped in the THS4032 in the main, and the intimacy dropped more, and the venue opened up without boosting the treble much.

Then the ISL55002 went in, and the treble came back up, soundstage remained wide open and not forward, and it reminded me of the 1364.

The 6172 went back in, and I still liked it more (although all of them sound good). Next I will try replacing the NE5532.

4) I put the DIP 6172 back in place of NE5532, while the SOIC/browndog 6172 was still in main, and left channel is gone again.

I put NE5532 back in and I have both channels.

So, I swapped the DIP version to the main, and moved the SOIC/browndog to the second IC = same missing lt channel. Then I pulled the SOIC from the secondary IC, put the NE5532 back in, both channels are back.

So, either 6172 works in main, but I can't use both or I lose left channel. Wierd.

So, I kept the DIP 6172 in LR, and pulled the NE5532 to install the THS4032. WOW! This combo works for me better than ISL55002 as the main opamp with the THS4032, which is more distant in the mids. But, the bass kinda big when using these HFI-780, but tolerable (any more bass and I'd be worried). With this cpmbo, the saxophone regains that magic, with a combination of BOTH warmth and reedyness. LIVE NIGHT CLUB JAZZ MUSIC SOUNDS LIVE. I am having difficulty changing this or stopping the music. "Help, I'm listening to music and I can't get up"!

You have to try the LM6172 in place of the 1364 and the THS4032 in place of the NE5532. I am leaving this alone for now. And still listening. Can't... pull... myself... away...

5) Then the D2 battery ran out. So, I set it aside to charge, and started playing with my 3G nano and Headsix, changing it to low gain for my livewires. Another Wow. I am still listening to that setup 2 hours later!



 
Apr 30, 2008 at 2:39 AM Post #14 of 126
Quote:

Originally Posted by powertoold /img/forum/go_quote.gif
Hey Headphone,

I didn't think the ISL55002 was that great either. The sound didn't feel natural. I didn't read your whole thing on the 6172, but maybe your BrownDog had a loose leg. The left channel thing happened to me too once; I'm not sure what I did.

Mrarroyo, almost all DIP opamps have a notch on one side (horizontally) that looks like a half-circle. On the circuit board, there is also a half-circle diagram. If you match up the two half-circles when you install the opamp, it should be fine. If you don't see the half-circle on your opamp, then line up the opamp to the socket in such a way that you can read the opamp normally (ie. left to right) when the half-circle on the circuit board is on your left.

Here is a picture (the BrownDog is also self-explanatory):

opamps.GIF



Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif
I really like the drawings. Can you please use stick figures to show how they are changed? :^)


biggrin.gif
biggrin.gif
biggrin.gif
 
Apr 30, 2008 at 2:51 AM Post #15 of 126
Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif
I put the 1364 back in the L/R and still like the 1364. I find it open, transparent and just plain enjoy the music. I found the same thing to be true on the P2. The 4032 is in the dip for the dac.


Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif
I like the more forward/warmer/less bright LM6172 in the main socket where the 1364 was (by the line and headphone jacks), and the THS4032 replacing the NE5532 by the power jack.

I still have to try the 1364 in main with THS4032 in the secondary socket. What have others heard with that combination?



Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif
That is what I am using, the 1364 in the L/R and the 4032 in the rear socket. I am getting decent width and depth and pleasing sound and very nice bass.


...
 

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